Chapter 11: Refrigeration Cycles

The main function of refrigeration systems or reversed heat engines is to transfer heat continuously from a low temperature region to a high temperature region using energy from an external source. In the more common applications of refrigeration, like food preservation and air conditioning, the aim of the refrigeration system is to maintain the temperature of the cold space below the local ambient temperature. The same system, however, may be used to heat the high temperature region by using the heat extracted from the cold region. It is then called a heat pump.